1. Field of Invention
The present invention relates to energy beam detection equipment, and more particularly, to an improved system for detecting the point of impact of an infrared laser beam remote from its point of transmission and providing a visual indication of the point of impact for alignment, targeting, verification and other purposes.
2. Description of Related Art
For many years the U.S. Army has trained soldiers with a multiple integrated laser engagement system (MILES). One aspect of MILES involves a small arms transmitter (SAT) being affixed to the barrel of a small arms weapon such as an M16A1 rifle or a machine. When the soldier pulls the trigger of his or her weapon blank cartridges are ignited to simulate the firing of an actual round or multiple rounds. An audio sensor and a photo-optic sensor in the SAT detect the firing of the blank round(s) and simultaneously energize an infrared laser diode in the SAT which emits an invisible energy beam of very short pulse duration toward a target which is in the conventional sights of the weapon. Each soldier is fitted with detectors on his or her helmet and on a body harness adapted to detect an invisible laser xe2x80x9cbulletxe2x80x9d hit.
According to one prior art approach, the SAT was bolted to the rifle barrel and the conventional sights of the weapon were adjusted to align with the laser beam. The disadvantage of this approach is that the conventional weapon sights had to be readjusted in order to use the rifle with live rounds. Thus the rifle was rendered useless for actual combat unless and until it was zeroed, i.e. the iron sights of the rifle were aligned by firing live ammunition at a target. To overcome this disadvantage, later SATs incorporated mechanical adjustors for manually changing the orientation, i.e. azimuth and elevation, of the laser beam.
Aligning a SAT has generally been performed using a fixture. One type of prior art small arms alignment fixture (SAAF) that has been used by the U.S. Army for aligning a manually adjustable SAT consists of a complex array of one hundred forty-four detectors which are used in conjunction with thirty-five printed circuit boards to determine where the laser hits with respect to a target. The prior art SAAF calculates the number of error xe2x80x9cclicksxe2x80x9d in both azimuth and elevation. The number of clicks is then displayed by the SAAF using four sets of electro-mechanical display indicators. A soldier must turn his or her SAT""s adjustors the corresponding number of clicks in the correct direction. He or she must then aim and fire the weapon again and make additional turns to the SAT""s adjustors. This iterative process continues until the soldier obtains a zero indication on the prior art SAAF.
A SAT which eliminates the need to utilize the prior art SAAF has been developed by Cubic Defense Systems, Inc. and deployed by the U.S. Army as part of Cubic""s MILES 2000(copyright) ground combat training system. The exercise events and casualties are recorded, replayed and analyzed in detail during xe2x80x9cafter action reviewsxe2x80x9d (AARs). The MILES 2000 SAT is automatically adjustable for more rapid and accurate alignment of its laser output. The MILES 2000 SAT features adjustable powers and encoding to enable the man-worn portion of the MILES 2000 system to discriminate between kills made by different small arms and different players.
The MILES 2000 SAT is disclosed in the aforementioned U.S. Pat. No. 5,476,385 of Parikh et. al. It uses a pair of optical wedges that are rotated to steer the laser beam and align the same with the optical or so-called xe2x80x9cironxe2x80x9d sights of the rifle. This approach, while achieving a reasonable degree of aligning the laser beam with the iron sights, requires a relatively expensive construction of the MILES 2000 SAT. This is attributable to the cost of the beam steering components such as the glass wedges, stainless steel gears, shafts, drive gears, housing, etc. The components must be small in size which makes mechanical design tolerances extremely tight. Furthermore the MILES 2000 SATxe2x80x94equipped rifle must be inserted into a portable box-like MILES 2000 automatic small arms alignment fixture (ASAAF) in order to accomplish the laser alignment in a semi-automatic fashion. See the aforementioned U.S. Pat. No. 5,410,815 of Parikh et al. The portable MiLES 2000 ASAAF is a relatively expensive device which itself must be calibrated.
It would therefore be desirable to provide a low cost alternative to the SAAF and the ASAAF that would provide visual feedback to a soldier firing a rifle equipped with a manually adjustable SAT by indicating the approximate horizontal and vertical location of the impact of the invisible infrared beam relative to a target in the iron sights of the rifle. This would allow the soldier to manually align the laser beam of the SAT to the iron sights of the rifle. Alternatively, for those SATs that do not permit the aim of their laser beams to be manually adjusted, the visual feedback could be used in aligning the iron sights of the weapon to the laser beam.
Accordingly, it is the primary object of the present invention to provide an improved system for detecting the point of impact of an energy beam remote from its point of transmission and providing a visual indication of the point of impact for alignment, targeting and other purposes.
In accordance with the present invention, a system is provided for detecting and visually indicating the relative location of the impact of an energy beam emitted from a remote source. A plurality of detectors are mounted on a target for generating output signals when struck by a beam of energy emitted from a remote source aimed at the target. A plurality of luminescent devices are mounted on the target for generating visible light when energized. A circuit is connected to the plurality of detectors for receiving the output signals. The circuit energizes preselected ones of the luminescent devices to provide a visual indication of a relative location of an impact on the target of the beam of energy. Although useful in a wide variety of applications, the system of the present invention may be advantageously employed in verifying the alignment of the invisible infrared laser beam emitted by a small arms transmitter (SAT) mounted on a rifle or other small arms weapon.
The present invention also provides a method of verifying an alignment of a beam of energy. The method includes the steps of providing a target and aiming a source remote from the target at the target, the source being capable of emitting a beam of energy. The method further includes the steps of causing the source to emit the beam of energy at the target, and detecting at the target, the location of an impact of the beam of energy on the target. The method further includes the step of providing, at the target, a visual indication of the location of the impact.